Exposure to organochlorine pesticides as a predictor to breast cancer: A case-control study among Ethiopian women

Breast cancer (BC) is becoming one of the most prevalent non-infectious disease in low and middle income countries. The steady rise of BC incidence may be related to the different risk factors. Among many, rampant presence of environmental pollutants might be one of the risk factors. Therefore, the aim of this study is to investigate exposure to organochlorine pesticides as a risk factor to breast cancer. A case-control study design was employed among breast cancer patients and non-breast cancer individuals (controls). Blood samples were collected from 100 study participants (50 cases and 50 controls) followed by serum separation, extraction and cleanup using standard analytical procdures. The findings revealed that ten organochlorine pesticides were detected in the serum of the study participants. From the detected organochlorine pesticides, heptachlor was observed at higher concentration for breast cancer patients (6.90±4.37 μg/L) and controls (9.15±3.84 μg/L). Mean serum level of p,p’-DDE, p,p’-DDT, heptachlor, gamma-chlordane, endosulfan, and dibutyl-chlorendate were significantly higher in the serum of breast cancer patients than the controls. From the studied pesticides, p,p’-DDT and gamma-chlordane are significant predictors for BC, while, others are equivocal. A unit increment of the concentration of p,p’-DDT (AOR; 2.03, 95% CI: 1.041–3.969) increased the odds of developing breast cancer by two, while for gamma-chlordane (AOR;3.12, 95% CI; 1.186–8.203) by three. Our study results suggesting that, organochlorines are a risk factors for breast cancer in Ethiopia. Decreasing exposure to such organochlorines might have a significant public health relevance in reducing non-communicable chronic illnesses. Besides, continues monitoring of persistent organic pollutants using body biomarkers is important for disease prevention and device mitigation measures.

Association of serum levels of p,p'- Dichlorodiphenyldichloroethylene (DDE) with type 2 diabetes in African American and Caucasian adult men from agricultural (Delta) and non-agricultural (non-Delta) regions of Mississippi

Epidemiological associations were reported in several studies between persistent organochlorine organic pollutants and type 2 diabetes mellitus (T2D). Mississippi is a highly agricultural state in the USA, particularly the Delta region, with previous high usage of organochlorine (OC) insecticides such as p,p'- dichlorodiphenyltrichloroethane (DDT). In addition, there is a high proportion of African Americans who display elevated prevalence of T2D. Therefore, this State provides an important dataset for further investigating any relationship between OC compounds and metabolic diseases. The aim of this study was to assess whether soil and serum levels of OC compounds, such as p,p'- dichlorodiphenyldichloroethylene (DDE), arising from the heavy historical use of legacy OC insecticides, might serve as an environmental public health indicator for T2D occurrence. Soil samples from 60 Delta and 60 non-Delta sites randomly selected were analyzed for the presence of OC compounds. A retrospective cohort study of adult men (150 from each region) was recruited to provide a blood sample for OC compound quantitation and select demographic and clinical information including T2D. Using multivariable logistic regression, an association was found between increasing serum DDE levels and T2D occurrence in non-Delta participants (those subjects with lower serum DDE levels), as opposed to Delta participants (individuals with higher serum DDE levels). Thus, while there was a relationship between serum DDE levels and T2D in those with lower burdens of DDE, the lack of association in those with higher levels of DDE indicates a complex non-monotonic correlation between serum DDE levels and T2D occurrence complicating the goal of finding a public health marker for T2D. Abbreviations: BMI, body mass index; CVD, cardiovascular disease; CDC, Center for Disease Control, United States of America; DDE, p,p'- dichlorodiphenyldichloroethylene; DDT, p,p'- dichlorodiphenyltrichloroethane; GC/MS, gas chromatography/mass spectrometry; GIS, geographic information system; GPS, global positioning system; HDL, high-density lipoprotein; HTN, hypertension; IDW, inverse distance weighting; IRB, Institutional Review Board; LDL, low-density lipoprotein; LOQ, limit of quantitation; NHANES, National Health and Nutrition Examination Surveys; POPs, persistent organic pollutants; OC, organochlorine; PCB, polychlorinated biphenyl; SIM, single-ion monitoring; T2D, type 2 diabetes mellitus; USA, United States of America.

Pre-diagnostic serum concentrations of organochlorines and risk of acute myeloid leukemia: A nested case-control study in the Norwegian Janus Serum Bank Cohort

BACKGROUND

Epidemiologic studies suggest an increased risk of leukemia among individuals occupationally exposed to some organochlorine (OC) compounds. Associations between serum OC pesticide and polychlorinated biphenyl (PCB) levels and risk of acute myeloid leukemia (AML), the most common subtype of acute leukemia in adult populations, have not been evaluated prospectively in the general population.

OBJECTIVE

We evaluated the risk of AML in relation to pre-diagnostic serum levels of OC pesticides and PCBs in a case-control study nested within the Janus Serum Bank Cohort.

METHODS

Janus is a large population-based cohort containing biologic samples collected beginning in the early 1970s from ~318,000 individuals in Norway. Serum levels of 11 OC pesticides or their metabolites and 34 PCB congeners were measured in 56 AML cases and 288 controls. Conditional logistic regression was conducted to evaluate associations between lipid-adjusted serum OC levels and risk of AML.

RESULTS

Higher serum levels of total chlordane/heptachlor metabolites were associated with AML risk (3rd vs. 1st tertile odds ratio (OR) = 2.26, 95% confidence interval (CI) = 0.91-5.63; p_trend = 0.11). Significant exposure-response associations were observed for levels of heptachlor epoxide (3rd vs. 1st tertile OR = 2.85, 95% CI = 1.05-7.73; p_trend = 0.02) and dieldrin (3rd vs. 1st tertile OR = 2.71, 95% CI = 1.07-6.83; p_trend = 0.03). No significant exposure-response associations with AML risk were observed for total DDT or individual isomers and derivatives. Higher serum levels of p,p'-DDT showed a non-significant increase in risk, but the exposure-response became attenuated when co-adjusting for heptachlor epoxide or dieldrin levels. Serum PCB levels were not significantly associated with AML risk.

CONCLUSIONS

Our data suggest that higher serum levels of dieldrin and metabolites derived from chlordane/heptachlor are associated with risk of AML in the general Norwegian population, based on samples collected on average ~17 years before diagnosis. Further research in populations with historically high or recent exposure to DDT is warranted to assess the association with AML risk with body burden of specific DDT isomers and derivatives.

Effects of biometrics, location and persistent organic pollutants on blood clinical-chemical parameters in polar bears (Ursus maritimus) from Svalbard, Norway

In the present study, blood clinical-chemical parameters (BCCPs) were analysed in 20 female and 18 male Svalbard polar bears (Ursus maritimus) captured in spring 2007. The aim was to study how age, body condition (BC), biometrics, plasma lipid content and geographical location may confound the relationship between persistent organic pollutants (POPs) including PCBs, HCB, chlordanes, DDTs, HCHs, mirex and OH-PCBs and the concentrations of 12 specific BCCPs (hematocrit [HCT], hemoglobin [HB], aspartate aminotransferase [ASAT], alanine aminotransferase [ALAT], γ-glutamyltransferase [GGT], creatine kinase [CK], triglycerides [TG], cholesterol [CHOL], high-density lipoprotein [HDL], creatinine (CREA], urea, potassium (K]), and to investigate if any of these BCCPs may be applied as potential biomarkers for POP exposure in polar bears. Initial PCA and O-PLS modelling showed that age, lipids, BC and geographical location (longitude and latitude) were important parameters explaining BCCPs in females. Following subsequent partial correlation analyses correcting for age and lipids, multiple POPs in females were still significantly correlated with HCT and HDL (all p < 0.05). In males, age, BM, BC and longitude were important parameters explaining BCCPs. Following partial correlation analyses correcting for age, biometrics, lipids and longitude in males, multiple POPs were significantly correlated with HCT, ASAT, GGT and CHOL (all p < 0.05). In conclusion, several confounding parameters has to be taken into account when studying the relations between BCCPs and POPs in polar bears. When correcting for these, in particular HCT may be used as a simple cost-efficient biomarker of POP exposure in polar bears. Furthermore, decreasing HDL concentrations and increasing CHOL concentration with increasing POP concentrations may indicate responses related to increased risk of cardiovascular disease. We therefore suggest to further study POP exposure and lipidome response to increase knowledge of the risk of cardiometabolic syndrome in polar bears.

Serum concentrations of organochlorine compounds and predictors of exposure in children living in agricultural communities from South-Eastern Spain

BACKGROUND

Information on exposure levels to organochlorine compounds (OCs) in child population is limited, despite their greater vulnerability to the adverse health effects of these chemicals.

OBJECTIVE

To determine serum concentrations of 10 OCs (including organochlorine pesticides and polychlorinated biphenyls -PCBs-) in children living in agricultural communities from Almería (South-Eastern Spain), and to identify the main predictors of exposure related to socio-economic characteristics, diet and lifestyle.

METHODS

A cross-sectional study was conducted on 133 children aged 6-11 years selected from public schools of the study area. OCs compounds were determined in serum samples by GC/ECD. Anthropometric measures were obtained during sample collection. Information on sociodemographic characteristics, parental occupation, residential history, lifestyle and frequency of food consumption, among other relevant factors, was obtained by questionnaires administered to the mothers.

RESULTS

Geometric means of serum concentrations (ng/ml) were 0.11 for β-hexachloro-cyclohexane (β-HCH), 0.09 for endosulfan, 0.20 for endosulfan-ether, 0.51 for hexachorobenzene (HCB), 0.08 for mirex, 0.06 for oxychlordane, 0.36 for p,p'-DDE, 0.20 for PCB 138, 0.36 for PCB 153, and 0.45 for PCB 180. Percentage of samples above the limit of detection (0.05 ppb) ranged from 32 (β-HCH) to 100 (HCB). A high variability in OC levels depending on the compound was observed between our results and others found in similar studies carried out in children. Variables related to fish consumption were found to be the major dietary determinant of PCB 138, p,p´-DDE, endosulfan-α, β-HCH, mirex and oxychlordane levels.

CONCLUSIONS

Children participating in this study showed detectable levels of many OC, despite these compounds are no longer used. Their presence in children serum can be explained by their high lipophilicity and environmental persistence, leading to contamination of fatty food. In this line, fish consumption seemed to be the most relevant determinant of OC levels found in our study.

Levels and profiles of organohalogenated contaminants in human blood from Egypt

Concentrations of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and some organochlorine pesticides (OCPs) were determined in serum of Egyptian colorectal cancer patients (n = 35) and compared to a healthy control group (n = 32). p,p'-DDE (the major metabolite of DDT) was the most frequently detected contaminant with the highest concentration (median = 131 ng/g lw) in all studied serum samples. BDE-209 was the least frequently detected contaminant with a median concentration <0.3 ng/g lw. The contamination profile in patients and controls was almost identical with p,p'-DDE showing the highest median contribution (77%) and oxychlordane the lowest (1%). The low p,p'-DDT/p,p'-DDE ratio (3.7%) in serum implies bioaccumulation and past exposure to DDT (c.f. recent and ongoing intake). Statistical analysis revealed no significant differences (P > 0.05) between the levels of target contaminants in serum of patients and the control group. Gender, age and body mass index (BMI) were investigated as potential factors influencing serum contaminant levels. ΣDDT, hexachlorobenzene and pentachlorophenol concentrations showed significant positive associations with age and/or BMI of the participants. Comparison with other countries revealed concentrations of PBDEs and PCBs in Egyptian serum among the lowest reported worldwide.

Association between Several Persistent Organic Pollutants in Serum and Adipokine Levels in Breast Milk among Lactating Women of Korea

Exposure to several persistent organic pollutants (POPs) has been linked to alteration of lipid metabolism. Adipokines, such as leptin and adiponectin, are hormones that play roles in lipid metabolism, and have been suggested as markers of health effects that may lead to obesity. To date, only serum adipokines have been associated with POPs exposure. In the present study, for the first time, the associations between leptin and adiponectin in breast milk, and several POPs in serum were investigated among 82 lactating Korean women between 25 and 46 years of age. Breast milk adipokines are important because adipokine intake of infant through breastfeeding may influence the growth of infants. The median concentrations of leptin and adiponectin in skimmed milk of the Korean lactating women were 17.9 ng/L and 16.5 μg/L, respectively. Leptin concentrations in breast milk were negatively associated with ∑hexachlorohexane (HCH), oxychlordane, ∑chlordane, or 2,2',4,4',5,5'-hexachlorobiphenyl (CB 153) levels in maternal serum. Linear relationships between adiponectin and POPs concentrations were not observed, however, nonmonotonic relationship which showed generally positive associations was suggested for p,p'-dichlorodiphenyltrichloroethane (DDT) and ∑chlordane in quartile analysis. Our observations show that POPs at the current level of exposure may be associated with the alteration of lipid metabolism among lactating women. Implication of adipokine transfer to breastfed infants is of concern and deserves further investigation.

Greater cognitive decline with aging among elders with high serum concentrations of organochlorine pesticides

Although cognitive decline is very common in elders, age-related cognitive decline substantially differs among elders and the determinants of the differences in age-related cognitive decline are unclear. We investigated our hypothesis that the association between age and cognition was stronger in those with higher serum concentrations of organochlorine (OC) pesticides, common persistent and strongly lipophilic neurotoxic chemicals. Participants were 644 elders aged 60-85, participating in the National Health and Nutrition Examination Survey 1999-2002. Six OC pesticides (p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodipenyldichloroethylene (DDE), β-hexachlorocyclohexane, trans-nonachlor, oxychlordane, and heptachlor epoxide) were evaluated. “Lower cognitive function” was defined as having a low Digit-Symbol Substitution Test (DSST) score (<25^th percentile of DSST score, cutpoint 28 symbols substituted). Higher levels of β-hexachlorocyclohexane, trans-nonachlor, oxychlordane, and heptachlor epoxide modified the associations between age and lower cognitive function (P_interaction<0.01, 0.03, <0.01, and 0.02, respectively). Elders in the 3^rd tertile of these chemicals demonstrated a greater risk of lower cognitive function with aging, compared to those in the combined 1^st and 2^nd tertiles. Among those with highest OC pesticides (3^rd tertile), the odds ratio for the risk of lower cognitive function was about 6 to 11 for the highest quintile of age (80-85 years) vs. the first quintile of age (60-63 years), while the association between age and lower cognitive function became flatter in those with lower OC pesticides (combined 1^st and 2^nd tertiles). Both DDT and DDE showed no interaction, with lower DSST scores for higher age irrespective of serum concentrations of DDT or DDE. Even though DSST score measures only one aspect of cognition, several OC pesticides modified aging-related prevalence of low cognitive score, a finding which should be evaluated in prospective studies.

Survival rate and breeding outputs in a high Arctic seabird exposed to legacy persistent organic pollutants and mercury

Chronic exposure to pollutants may represent a threat for wildlife. We tested whether adult survival rate, breeding probability and breeding success the year of sampling and the following year were affected by blood levels of mercury or persistent organic pollutants in Svalbard black-legged kittiwake Rissa tridactyla, by using capture-mark-recapture models over a five-year period. Survival rate was negatively linked to HCB levels in females, to chlordane mixture and oxychlordane, tended to decrease with increasing PCBs or DDE levels, but was unrelated to mercury. Breeding probability decreased with increasing mercury levels during the sampling year and with increasing CHL or HCB levels during the following year, especially in males observed as breeders. Surprisingly, the probability of raising two chicks increased with increasing HCB levels. Although levels of these legacy pollutants are expected to decline, they represent a potential threat for adult survival rate and breeding probability, possibly affecting kittiwake population dynamics.

Body burden of metals and persistent organic pollutants among Inuit in the Canadian Arctic

Inuit living in the Arctic are exposed to elevated levels of environmental contaminants primarily due to long-range atmospheric transport. Blood sampling and contaminant biomonitoring was conducted as part of the International Polar Year Inuit Health Survey in 2007-2008. The body burden of metals (e.g. Cd, Pb) and persistent organic pollutants (e.g. PCBs, DDT & DDE, toxaphene, chlordane, PBDEs) were measured for Inuit participants (n=2172) from 36 communities in Nunavut, Nunatsiavut, and the Inuvialuit Settlement Region, in Canada. The geometric mean of blood concentrations for Cd, Pb, PCBs, DDE & DDT, toxaphene, and chlordane were higher than those in the Canadian general population. A total of 9% of study participants exceeded the intervention guideline of 100μgL(-1) for Pb, 11% of participants exceeded the trigger guideline of 5μgL(-1) for Cd, and 1% exceeded the intervention guideline of 100μgL(-1) for PCBs. Also, 3% of women of child-bearing age exceeded blood Pb of 100μgL(-1) while 28% of women of child-bearing age exceeded 5μgL(-1) of PCBs. This work showed that most Inuit Health Survey participants were below blood contaminant guidelines set by Health Canada but that metal and POP body burdens commonly exceed exposures observed in the general population of Canada.

Circulating metals and persistent organic pollutant concentrations in Canadian and non-Canadian born primiparous women from five Canadian centres: results of a pilot biomonitoring study

The developing foetus is thought to be at increased risk from exposure to environmental contaminants; however, developmental exposure data is notably lacking for many contaminants. Moreover, potential regional differences or effect of place of birth on residue levels measured in pregnant women is also unknown. Therefore, as part of a multinational biomonitoring study, 125 primiparous pregnant Canadian women were recruited from five Canadian centres (Vancouver, Calgary, Hamilton, Ottawa, and Halifax). Metals in whole blood and persistent organic pollutants (POPs) in plasma were measured by inductively coupled plasma mass spectrometry (ICPMS) and gas chromatography-mass spectrometry (GCMS), respectively. Of the 125 women recruited to this study, complete data sets were available for 123 of which 103 were Canadian born. Data were analysed by analysis of covariance and linear mixed models using age and body mass index as covariates. The metals cadmium (Cd), cobalt (Co), lead (Pb), nickel (Ni), selenium (Se), and total mercury (Hg) were detected in more than 93% of the samples tested. β-Hexachlorohexane (β-HCH), oxychlordane, trans-nonachlor, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), polybrominated diphenyl ether (PBDE) congeners (PBDE-153, PBDE-47), polychlorinated biphenyl (PCB) congeners (PCB-138, -153, and -180), and the dioxin-like PCB congener PCB-118 were quantified in greater than 70% of the samples tested. Significant differences in the concentrations of Cd, Ni, PCB-153, and p,p'-DDE were found between the centres studied. Furthermore, foreign-born pregnant women had significantly higher concentrations of Cd, β-HCH, PBDE-47, PCB-138, -153, -180, and p,p'-DDE compared to Canadian born pregnant women. Taken together, the data suggest that there are potential regional differences in contaminant body burden and place of birth may also contribute to differences in maternal residue concentrations.

Levels of selected persistent organic pollutants in blood from delivering women in seven selected areas of São Paulo State, Brazil

Persistent organic pollutants (POPs) present in the living environment are thought to have detrimental health effects on the population, with pregnant women and the developing foetus being at highest risk. We report on the levels of selected POPs in maternal blood of 155 delivering women residing in seven regions within the São Paulo State, Brazil. The following selected POPs were measured in the maternal whole blood: 12 polychlorinated biphenyls (PCBs) congeners (IUPAC Nos. 99, 101, 118, 138, 153, 156, 163, 170, 180, 183, 187, 194); dichlordiphenyltrichloroethane p,p'-DDT, diphenyldichloroethylene p,p'-DDE and other pesticides such as hexachlorocyclohexanes (α-HCH, β-HCH, γ-HCH), hexachlorobenzene (HCB), chlordane derivatives cis-chlordane, trans-chlordane, oxy-chlordane, cis-nonachlor and trans-nonachlor. Statistical comparisons between regions were performed only on compounds having concentrations above LOD in 70% of the samples. PCB118 congener was found to be highest in the industrial site (mean 4.97 ng/g lipids); PCB138 congener concentration was highest in the Urban 3 site (mean 4.27 ng/g lipids) and congener PCB153 was highest in the industrial and Urban 3 sites with mean concentration of 7.2 ng/g lipids and 5.89ng/g lipids respectively. Large differences in levels of p,p'-DDE between regions were observed with the Urban 3 and industrial sites having the highest concentrations of 645 ng/g lipids and 417 ng/g lipids, respectively; β-HCH was found to be highest in the Rural 1 site; the γ-HCH in Rural 1 and industrial; the HCB in the Rural 1 and industrial sites and oxy-chlordane and t-NC in the Rural 2 sites. An association between levels of some contaminants and maternal age and parity was also found.

Maternal pregnancy levels of trans-nonachlor and oxychlordane and prevalence of cryptorchidism and hypospadias in boys

BACKGROUND

The etiologies of the male urogenital anomalies--cryptorchidism and hypospadias--are poorly understood. Given positive associations between chlordane isomers and testicular germ cell tumors, it is reasonable to assume that chlordanes might also be associated with other testicular dysgenesis syndrome disorders, namely cryptorchidism and hypospadias.

OBJECTIVE

To examine whether exposure to in utero chlordane is related to cryptorchidism and hypospadias, we evaluated levels of chlordane derivatives, trans-nonachlor and oxychlordane, among pregnant women enrolled in the Collaborative Perinatal Project (CPP).

METHODS

From 1959 to 1965, the CPP enrolled pregnant women at 12 U.S. medical centers. We analyzed serum trans-nonachlor and oxychlordane levels measured in third-trimester serum from the mothers of 217 sons with cryptorchidism, 197 sons with hypospadias, and 557 sons with neither condition. Adjusted odds ratios (ORs) and 95% confidence intervals were calculated using conditional logistic regression.

RESULTS

The quartile-specific ORs for cryptorchidism or hypospadias show no notable associations with trans-nonachlor or oxychlordane. Further, there were no significant trends with increasing quartile of maternal trans-nonachlor or oxychlordane level in either cryptorchidism or hypospadias (p-trend all > 0.45).

CONCLUSIONS

The results do not support an association between chlordane levels and cryptorchidism or hypospadias. It is unlikely that current chlordane exposure is related to the development of either anomaly, given that serum chlordane levels at the time of sample collection, the early 1960s, were considerably higher than levels at present.

Accumulation dynamics of chlordanes and their enantiomers in cockerels (Gallus gallus) after oral exposure

After a single oral exposure of technical chlordane, levels of cis-chlordane (CC), trans-chlordane (TC), heptachlor (HEP), heptachlorepoxide (HEPX), and oxychlordane (OXY) were determined in gastrointestinal residues, droppings, and various tissues of cockerels at times of 60, 120, 160, 200, 300, 500, 1000, and 2000 min. Over 98% of CC and TC were found to be bioaccessible; only 1.1% of CC and TC were directly excreted through droppings without further biotransformation. According to the single-compartment toxicokinetic modeling, CC and TC shared similar absorption rates in the whole body while TC showed a slightly more rapid elimination rate, with a half-life of 13.4 h for CC and 12.5 h for TC. The metabolites HEPX and OXY appeared quickly in tissues 60 min after exposure and were mainly accumulated in fat and liver tissues. Concentrations of CC, TC, and HEP in cockerel tissues roughly followed the order as fat > intestine > skin > liver> brain > muscle > blood. Levels of CC, TC, and HEP in various tissues showed significant correlation with the lipid contents of the tissues (p < 0.05) for samples beginning 500 min after exposure. A multicompartment toxicokinetic model was developed to characterize the accumulation dynamics of CC and TC in the various tissues. All tissues of cockerels enantioselectively accumulated (-)-CC and (+)-TC, and fat, skin, and liver tissues showed a relatively stronger capacity of enantioenrichment. The enantiomer fractions (EFs) of droppings remained nearly racemic at first but gradually decreased to less than 0.5 for CC and increased to more than 0.5 for TC, which could rule out enantioselective absorption and excretion of CC and TC in cockerels. The one-compartment toxicokinetic model was applied to the individual enantiomers of CC and TC. Different elimination rates but similar absorption rates were observed between the enantiomers for both CC and TC.

Fetal exposure to chlordane and permethrin mixtures in relation to inflammatory cytokines and birth outcomes

We sought to characterize the relationships between cord serum concentrations of chlordane and permethrin pesticides, inflammatory cytokines, gestational age, and size at birth. Umbilical cord serum levels of trans-nonachlor, oxychlordane, cis- and trans-permethrin, piperonyl butoxide, and cytokines (TNF-α, IFN-γ, IL-1β, IL-2, IL-6, IL-8, IL-10, IL-12p70, GMCSF) were quantified in 300 newborns at the Johns Hopkins Hospital in Baltimore, MD (2004-2005). Principal component analyses were used to quantitate chlordane and permethrin mixtures and to identify independent cytokine components. Five cytokine components described 87% of the variance in cord serum cytokine levels; these (and predominant loadings) were as follows: (1) all 9 cytokines; (2) acute phase (IL-1β, IL-6); (3) anti-inflammatory (IL-10); (4) TNF-α; and (5) IL-1β. Of these, the TNF-α component was significantly associated with a 2-day decrease in gestational age. Chlordane was associated with lower levels of the pro-inflammatory IL-1β [β: -0.11 (-0.20, -0.02)]. Permethrin was negatively associated with the anti-inflammatory cytokine IL-10 [β: -0.14 (-0.22, -0.05)]. Neither pesticides nor cytokines were significantly associated with birthweight, length, or head circumference, and pesticides were not associated with gestational age. Our findings suggest that chlordane and permethrin concentrations in cord blood may be associated with levels of inflammatory cytokines in the fetus.

A screening of persistent organohalogenated contaminants in hair of East Greenland polar bears

In this pilot study, we report on levels of persistent organohalogenated contaminants (OHCs) in hair of polar bears (Ursus maritimus) from East Greenland sampled between 1999 and 2001. To our knowledge, this is the first study on the validation of polar bear hair as a non-invasive matrix representative of concentrations and profiles in internal organs and blood plasma. Because of low sample weights (13-140mg), only major bioaccumulative OHCs were detected above the limit of quantification: five polychlorinated biphenyl (PCB) congeners (CB 99, 138, 153, 170 and 180), one polybrominated diphenyl ether (PBDE) congener (BDE 47), oxychlordane, trans-nonachlor and β-hexachlorocyclohexane. The PCB profile in hair was similar to that of internal tissues (i.e. adipose, liver, brain and blood), with CB 153 and 180 as the major congeners in all matrices. A gender difference was found for concentrations in hair relative to concentrations in internal tissues. Females (n=6) were found to display negative correlations, while males (n=5) showed positive correlations, although p-values were not found significant. These negative correlations in females may reflect seasonal OHC mobilisation from periphery adipose tissue due to, for example, lactation and fasting. The lack of significance in most correlations may be due to small sample sizes and seasonal variability of concentrations in soft tissues. Further research with larger sample weights and sizes is therefore necessary to draw more definitive conclusions on the usefulness of hair for biomonitoring OHCs in polar bears and other fur mammals.

Time trends of persistent organic pollutants in Sweden during 1993-2007 and relation to age, gender, body mass index, breast-feeding and parity

BACKGROUND

Persistent organic pollutants (POPs) are lipophilic chemicals that bioaccumulate. Most of them were resticted or banned in the 1970s and 1980s to protect human health and the environment. The main source for humans is dietary intake of dairy products, meat and fish. Little data exist on changes of the concentration of POPs in the Swedish population over time.

OBJECTIVE

To study if the concentrations of polychlorinated biphenyls (PCBs), DDE, hexachlorobenzene (HCB) and chlordanes have changed in the Swedish population during 1993-2007, and certain factors that may influence the concentrations.

METHODS

During 1993-2007 samples from 537 controls in different human cancer studies were collected and analysed. Background information such as body mass index, breast-feeding and parity was assessed by questionaires. Wilcoxon rank-sum test was used to analyse the explanatory factors specimen (blood or adipose tissue), gender, BMI, total breast-feeding and parity in relation to POPs. Time trends for POPs were analysed using linear regression analysis, adjusted for specimen, gender, BMI and age.

RESULTS

The concentration decreased for all POPs during 1993-2007. The annual change was statistically significant for the sum of PCBs -7.2%, HCB -8.8%, DDE -13.5% and the sum of chlordanes -10.3%. BMI and age were determinants of the concentrations. Cumulative breast-feeding >8 months gave statistically significantly lower concentrations for the sum of PCBs, DDE and the sum of chlordanes. Parity with >2 children yielded statistically significantly lower sum of PCBs.

CONCLUSIONS

All the studied POPs decreased during the time period, probably due to restrictions of their use.

Low dose of some persistent organic pollutants predicts type 2 diabetes: a nested case-control study

BACKGROUND

Low doses of some persistent organic pollutants (POPs) associate cross-sectionally with type 2 diabetes, whereas associations with high POP exposures are inconsistent.

OBJECTIVES

We investigated whether several POPs prospectively predict type 2 diabetes within the Coronary Artery Risk Development in Young Adults (CARDIA) cohort.

METHODS

Participants in this nested case-control study were diabetes free in 1987-1988. By 2005-2006, the 90 controls remained free of diabetes, whereas the 90 cases developed diabetes. Using serum collected in 1987-1988, we measured 8 organochlorine pesticides, 22 polychlorinated biphenyl congeners (PCBs), and 1 polybrominated biphenyl (PBB). We compared POP concentrations from CARDIA and the National Health and Nutrition Examination Survey (NHANES) in 2003-2004. We computed odds ratios (ORs) for incident diabetes using logistic regression analysis.

RESULTS

Chlorinated POPs in CARDIA in 1987-1988 were much higher than corresponding NHANES 2003-2004 concentrations. POPs showed nonlinear associations with diabetes risk. The highest risk was observed in the second quartiles of trans-nonachlor, oxychlordane, mirex, highly chlorinated PCBs, and PBB153-a finding that suggests low-dose effects. We concentrated risk by summing these POPs and isolated very low concentrations of multiple POPs in the lowest sextile of the sum. The adjusted OR in the second sextile vs. the lowest sextile was 5.3 overall and 20.1 for body mass index > or = 30 kg/m2.

CONCLUSIONS

Several POPs at low doses similar to current exposure levels may increase diabetes risk, possibly through endocrine disruption. Certain POPs may a play a role in the current epidemic of diabetes, which has been attributed to obesity.

Prediagnostic serum concentrations of organochlorine compounds and risk of testicular germ cell tumors

BACKGROUND

Recent findings suggest that exposure to organochlorine (OC) compounds, chlordanes and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in particular, may increase the risk of developing testicular germ cell tumors (TGCTs).

OBJECTIVE

To further investigate this question, we conducted a nested case-control study of TGCTs within the Norwegian Janus Serum Bank cohort.

METHODS

The study was conducted among individuals with serum collected between 1972 and 1978. TGCT cases diagnosed through 1999 (n = 49; 27-62 years of age at diagnosis) were identified through linkage to the Norwegian Cancer Registry. Controls (n =51) were matched to cases on region, blood draw year, and age at blood draw. Measurements of 11 OC insecticide compounds and 34 polychlorinated biphenyl (PCB) congeners were performed using gas chromatography/high-resolution mass spectrometry. Case-control comparisons of lipid-adjusted analyte concentrations were performed using the Wilcoxon signed-rank test. Odds ratios (ORs) and 95% confidence intervals (CIs) for tertiles of analyte concentration were calculated using conditional logistic regression.

RESULTS

TGCT cases had elevated concentrations of p,p'-DDE (tertile 3 vs. tertile 1 OR (OR(T3)) 2.2; 95% CI, 0.7-6.5; p(Wilcoxon) = 0.07), oxychlordane (OR(T3) 3.2; 95% CI, 0.6-16.8; p(Wilcoxon) = 0.05), trans-nonachlor (OR(T3) 2.6; 95% CI, 0.7-8.9; p(Wilcoxon) = 0.07), and total chlordanes (OR(T3) 2.0; 95% CI, 0.6-7.2; p(Wilcoxon) = 0.048) compared with controls, although no ORs were statistically significant. Seminoma cases had significantly lower concentrations of PCB congeners 44, 49, and 52 and significantly higher concentrations of PCBs 99, 138, 153, 167, 183, and 195.

CONCLUSIONS

Our study provides additional but qualified evidence supporting an association between exposures to p,p'-DDE and chlordane compounds, and possibly some PCB congeners, and TGCT risk.

Chiral organochlorine contaminants in blood and eggs of glaucous gulls (Larus hyperboreus) from the Norwegian Arctic

Glaucous gulls (Larus hyperboreus) and their eggs from Svalbard (Norwegian Arctic) have been used as biomonitors of contaminants in the marine environment. In this study, the enantiomer fractions (EFs) of chiral chlordanes and atropisomeric polychlorinated biphenyl (PCB) congeners were determined in the blood plasma of adult male and female glaucous gulls from three breeding colonies in Svalbard. Plasma EFs were similar in magnitude and direction to EFs previously reported in glaucous gulls from other arctic food webs, suggesting overall similarities in the biochemical processes influencing the EFs of bioaccumulated organochlorine (OC) contaminants within the food webs at those locations. Additionally, EFs in yolk of eggs collected concurrently from within the same nesting colonies varied with location, laying date, and OC concentrations, and may be influenced by changes in the local feeding ecology between those colonies. No differences were found between the EFs for any analyte in female gulls compared to those found in egg yolk, indicating that processes involved in the maternal transfer of chlordanes and PCBs to eggs do not modulate the stereochemical ratio between enantiomers. Therefore, the use of eggs as a valuable and noninvasive means of OC biomonitoring may also extend to enantiomer compositions in glaucous gulls, and perhaps also in other seabird species from arctic regions.

Anti-parasite treatment removes negative effects of environmental pollutants on reproduction in an Arctic seabird

Recent studies have shown that the detrimental effects of anthropogenic pollutants may be worse if organisms are exposed to natural stress. In this study, we examined whether negative effects of organochlorines (OCs) could be influenced by parasites. In two breeding seasons, we administered an anti-helminthic drug to groups of breeding glaucous gulls (Larus hyperboreus), whereas control groups were placebo treated. In all birds, blood residues of the most important OCs in the study population (hexachlorobenzene, oxychlordane, p,p'-dichlorodiphenyldichloroethylene and polychlorinated biphenyl), were measured. The relationships between OCs and fitness components (i.e. nesting success and return rate between breeding seasons) were then compared between the birds receiving anti-parasite treatment and the controls. Among untreated males, higher blood residues of OCs were associated with lowered nesting success, while in males receiving anti-parasite treatment, there was no detrimental effect of OCs on fitness. Return rate was not affected by treatment or OCs. Our findings suggest that parasites may be an important factor in triggering reproductive effects of such pollutants, and that relatively low levels of OCs may have serious reproductive consequences in natural populations when stress from other sources is high.

Organochlorines and risk of non-Hodgkin lymphoma

Organochlorine chemicals and polychlorinated biphenyls (PCBs) have been suspected as possible risk factors for non-Hodgkin lymphoma (NHL). We investigated PCBs and organochlorine pesticides and risk of NHL in a population-based case-control study in British Columbia, Canada. Congeners of PCBs (including dioxinlike congeners) and pesticides or pesticide metabolites were measured in plasma of 422 pretreatment cases and 460 control subjects. This is so far the largest study to examine organochlorines in plasma to date. Several dioxin-like PCB congeners were associated with increased risk of NHL, including dioxin-like PCB nos. 118 and 156 with odds ratios (OR) for the highest versus lowest quartile between 1.6 and 1.8. Several non-dioxin-like congeners also showed significant associations. The PCB congener with the strongest association was no. 180 with an OR for the highest versus the lowest quartile of 1.83 (95% confidence interval = 1.18-2.84). Six pesticide analytes also showed a significant association with NHL; beta-hexachlorocyclohexane, p,p'-DDE, hexachlorobenzene, mirex, oxychlordane and trans-nonachlor. The strongest association was found for oxychlordane, a metabolite of the pesticide chlordane (highest vs. lowest quartile OR = 2.68, 95% confidence interval = 1.69-4.24). Our results provide further evidence that organochlorines contribute to NHL risk.

Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: associations with basal metabolism and circulating thyroid hormones

Exposure to organohalogens in endotherms has been suggested to impose chemically induced stress by affecting functions related to maintenance energy requirements. Effects on basal metabolic rate (BMR) have been suggested to be, in part, mediated through interactions with the thyroid hormones (THs). We investigated the relationships between plasma concentrations of major organochlorines, PBDEs, hydroxylated (OH)- and methoxylated (MeO)-PBDEs and OH-PCBs, circulating TH levels and BMR in breeding glaucous gulls (Larus hyperboreus) from the Norwegian Arctic. Negative associations were found between BMR and concentrations of sigma PCB, Sigma DDT and particularly Sigma chlordane, which combined made up 91% of the total contaminant burden. Levels of THs (thyroxine and triiodothyronine) were not associated significantly with variation of BMR or concentrations of any of the compounds determined. The present study suggests that BMR may be altered in glaucous gulls exposed to high loadings of persistent contaminants in the Norwegian Arctic environment.

A strong dose-response relation between serum concentrations of persistent organic pollutants and diabetes: results from the National Health and Examination Survey 1999-2002

OBJECTIVE

Low-level exposure to some persistent organic pollutants (POPs) has recently become a focus because of their possible link with the risk of diabetes.

RESEARCH DESIGN AND METHODS

Cross-sectional associations of the serum concentrations of POPs with diabetes prevalence were investigated in 2,016 adult participants in the National Health and Nutrition Examination Survey 1999-2002. Six POPs (2,2',4,4',5,5'-hexachlorobiphenyl, 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin, oxychlordane, p,p'-dichlorodiphenyltrichloroethane, and trans-nonachlor) were selected, because they were detectable in >or=80% of participants.

RESULTS

Compared with subjects with serum concentrations below the limit of detection, after adjustment for age, sex, race and ethnicity, poverty income ratio, BMI, and waist circumference, diabetes prevalence was strongly positively associated with lipid-adjusted serum concentrations of all six POPs. When the participants were classified according to the sum of category numbers of the six POPs, adjusted odds ratios were 1.0, 14.0, 14.7, 38.3, and 37.7 (P for trend < 0.001). The association was consistent in stratified analyses and stronger in younger participants, Mexican Americans, and obese individuals.

CONCLUSIONS

There were striking dose-response relations between serum concentrations of six selected POPs and the prevalence of diabetes. The strong graded association could offer a compelling challenge to future epidemiologic and toxicological research.

Age at natural menopause and exposure to organochlorine pesticides in Hispanic women

A cross-sectional study was conducted to evaluate the relationship between exposure to selected organochlorine pesticides (OCP) (p,p'-DDT, p',p'-DDE, dieldrin, hexachlorobenzene, beta-hexachlorocyclohexane [beta-HCH], oxychlordane, trans' nonachlor) and age at natural menopause in a sample of 219 menopausal women participating in the Hispanic Health and Nutrition Examination Survey in 1982-1984. Information on age at menopause, reproductive history, demographic variables, and potential confounding variables was collected via interview. Analysis of variance was employed to compare adjusted mean age at natural menopause among women by category of serum OCP level. Serum levels of p,p'-DDT, p,p'-DDE, beta-HCH, and trans-nonachlor were associated with a younger age at menopause. In particular, women with exposure levels in the highest exposure categories (serum p,p'-DDT > or = 6ppb, beta-HCH > or = 4ppb, or trans-nonachlor > or = 2ppb) had an adjusted mean age at menopause on average 5.7, 3.4, and 5.2 yr earlier, respectively, than women with serum levels of these pesticides below the detection limit. Women with serum p,p'-DDE levels greater than 23.6 ppb (highest quintile) had an adjusted mean age at menopause 1.7 yr earlier than women with serump,p'-DDE levels less than 5.5 ppb (lowest quintile). However, no consistent dose-response effect was apparent across low, medium, and high exposure categories. Interactions were detected for p,p'-DDT in combination with beta-HCH, trans-nonachlor, or oxychlordane, as well as beta-HCH in combination with oxychlordane.

Xenoestrogens: do they lower survival after thermal injury?

The effect of hormone disruptors on human health is an area of recent concern. The authors measured heptachlor epoxide and oxychlordane--the body storage forms of estrogenic insecticides-in the sera of patients with major burns (i.e., 7 survivors and 10 age- and burn-size-matched nonsurvivors) on days 1, 3, 5, 7, and 11 after they had been burned, as well as in 12 age-matched normal controls. During the hypermetabolic phase, serum concentrations of heptachlor epoxide and oxychlordane were greater in nonsurvivors than in controls, and heptachlor epoxide concentrations in nonsurvivors exceeded those in survivors on postburn day 5. The postburn alterations in heptachlor epoxide and oxychlordane concentrations could not be accounted for by changes in concentrations of circulating lipid. These findings, which indicate that xenoestrogens are released from fat depots after thermal injury, suggest a possible contribution to mortality, especially in older patients.

Is DDT exposure during fetal period and breast-feeding associated with neurological impairment?

The concentration of certain persistent organic pollutants was determined in a family including both parents and one son with neurological impairment suggested to be Attention Deficit-Hyperactivity Disorder (ADHD). For comparison control subjects from other ongoing studies were used. They were of the same sex and age group as the respective family member. For polychlorinated biphenyls, hexachlorobenzene, and chlordanes similar results were found in the study groups. The concentration of DDE, the main metabolite of DDT, was increased in the mother, 782 ng/g lipid, compared with mean 403, median 259 (range 51-1354) for the female controls. Also, the son had an increased concentration of 259 ng/g lipid, compared with mean 104, median 72 (range 46-349) for controls. A low concentration was found in the father, 127 ng/g lipid. As a child and as a teenager to the age of 17, the mother was exposed to DDT in her home environment. We discuss the potential of fetal and breast-feeding exposure of the son. Neurodevelopmental impairment has been reported for dioxins and PCBs, but DDT seems to have been less investigated in this respect.

Case-control study on concentrations of organohalogen compounds and titers of antibodies to Epstein-Barr virus antigens in the etiology of non-Hodgkin lymphoma

A rapid increase in incidence of non-Hodgkin lymphoma (NHL) has been reported from many countries. Exposure to certain pesticides and organochlorines has been shown to be risk factors. Epstein-Barr virus (EBV) is a human herpesvirus that has been associated with some subgroups of NHL, such as Burkitt lymphoma and lymphomas related to severe immunosuppression. In this study, we measured lipid adjusted blood concentrations of 36 congeners of polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl-dichloroethylene (p,p'-DDE), hexachlorobenzene (HCB), four different subgroups of chlordanes (trans-nonachlordane, cis-nonachlordane, MC6 and oxychlordane) and 2,2',4,4'-tetrabrominated diphenyl ether (TBDE) in incident cases of NHL and controls from the general population. Titers of antibodies to the Epstein-Barr early antigen (EA) were correlated to concentrations of organochlorines. We found a significant difference in lipid adjusted blood concentrations of total PCBs and TBDE between cases and controls. Titers of antibodies to EA IgG > 80 were correlated to an increased risk for NHL with odds ratio (OR) = 1.9, 95% confidence interval (CI) =0.94-3.8. This risk was further increased in those with a level above the median value of "sum of PCBs" (OR=4.0, CI=1.2-14), HCB (OR=5.3, CI=1.6-19), sum of chlordanes (OR=4.0, CI=1.2-14) and TBDE (OR=21, CI=4.6-124), suggesting an interaction between EBV and a higher concentration of these chemicals. Also for the "sum of immunotoxic PCBs" increased risk was found in that group (OR=6.4, CI=1.9-24). Subdivision of NHL in histological types yielded highest risks for low-grade B-cell NHL.

The effects of chlordane exposure during pre- and postnatal periods at environmentally relevant levels on sex steroid-mediated behaviors and functions in the rat

Technical chlordane is a mixture of four main isomers (i.e., heptachlor, cis-chlordane, trans-chlordane, and trans-non-achlor) found in meat and dairy products as well as in indoor air of houses treated for termites. These isomers are metabolized to more potent epoxides (heptachlor epoxide and oxychlordane) which accumulate in lipid compartments of tissues and have been shown to reduce chloride influx through GABAA receptor complex channels and to alter steroid levels. However, considering the almost universal human exposure and the potential for accumulation of these agents, very little is known about how chronic, low-level exposures during development affect adult behavior and steroid-mediated processes. Time-pregnant Sprague-Dawley dams (Day 4 of gestation through Day 21 of lactation) and offspring (Day 22 of age through Day 80) were exposed to three levels of technical chlordane (100, 500, or 5000 ng/g) on a daily schedule. The low-exposure level generated heptachlor epoxide and oxychlordane plasma levels in the dam (Day 20) and in the offspring (Day 80) representative of those found in the U.S. populace. Chlordane-dosed offspring exhibited sex- and dose-dependent effects on testosterone levels, behavioral tests, and body weight conducted between postnatal Days 77 and 85. Chlordane-dosed females, but not males, had significant decreases in testosterone levels, significant improvements in spatial abilities (i.e., decreases in Cincinnati maze errors, navigation times, and failures to escape), and significant increases in body weight and in auditory startle-evoked responses. In two other tests, only males were used. These chlordane-dosed males showed significant increases in male-typical mating behaviors and decreases in 36Cl- uptake into brain microsacs. For all behavioral and body weight measurements, dose-response effects were observed for the 100 and 500 ng/g dosed groups. However, the 5000 ng/g dose group responses were closer to those of control values. These results suggest that these cyclodienes masculinize sexually dimorphic functions and behaviors by mimicking sex steroids and/or changing their levels.

Heptachlor, heptachlor epoxide, and other chlordane compounds in Finnish plywood workers

Residue levels of heptachlor, heptachlor epoxide, and other chlordane compounds were determined in sera from 74 Finnish plywood workers and 52 controls. Concentrations of heptachlor epoxide in plywood workers varied from below the detection limit of 0.1 ng/g to 19.2 ng/g serum (conversion factor for SI units = 975 [1 ng/g = 0.98 microgram/l]); the mean and standard deviation were 3.2 and 3.9 ng/g, respectively. Heptachlor expoxide values in controls varied from below the detection limit to 1.2 ng/g serum. The exposure time, i.e., number of years spent working with sizings that contained heptachlor, correlated with the residue levels of heptachlor epoxide that were measured in serum samples taken from employees at two companies (p = .03). The most common chlordane compound (contaminant of heptachlor) found in the sera of plywood workers was trans-nonachlor; also found were high concentrations of heptachlor epoxide. Headache, dizziness, and eye irritation were not related to serum levels of heptachlor or chlordane compounds.

Effects of chlordane on parameters of liver and muscle toxicity in man and experimental animals

An attempt was made to compare the toxic effects of the organochlorine insecticide 'chlordane' in man and rats. Analysis of blood for chlordane metabolites showed their presence in the descending order of trans-nonachlor, oxychlordane, heptachlorepoxide and cis-nonachlor. The total range of chlordane and its metabolites in the sera of workers was 9.84 +/- 4.47 ng/g. Serum levels of triglycerides (TG), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) activities were also found to be higher in pest-control operators. In a simultaneous study, rats were administered 100 mg/kg body wt. of chlordane by stomach tube once a day for 4 days, whereas 50 mg/kg body wt. of chlordane was injected intraperitoneally once a day for 4 days. The data show that total cholesterol and serum TG as well as CPK and LDH activities are increased after chlordane treatment. The isoenzyme patterns suggest that an increase in CPK and LDH is related to skeletal muscle. Furthermore, the hepatotoxicity of chlordane was also studied in rats only. A significant increase in liver weight, its water content, total lipids, triglycerides and phospholipids was recorded. Chlordane induced lipid peroxidation in the liver, exhibiting a dose-response relationship. Although no appreciable effect on mitochondrial function and latent ATPase activity was observed, 2,4-dinitrophenol-stimulated ATPase activity was inhibited. Histological examination of the liver confirmed fatty infiltration induced by chlordane in rats.

Residues in beef cattle accidentally exposed to commercial heptachlor

The changes in concentration of heptachlor epoxide (HCE) and oxychlordane (OCD) were studied in the tissues of beef cattle that had previously grazed pasture contaminated with commercial heptachlor. In 25 cows and heifers monitored over 488 days, the mean concentration of HCE decreased from 22.0 to 0.08 mg/kg and of OCD from 5.68 to 0.18 mg/kg. The respective half-lives were estimated to be 66 and 92 days. In a controlled feeding experiment, nine steers were subjected to one of three dietary regimes; a high plane of nutrition for 81 days then a low plane for 140 days; a moderate plane of nutrition for the total period; and a low plane of nutrition for 81 days then a high plane for 140 days. Approximately five months later similar treatments were applied for 101 and 94 days. The rate of decline of HCE and OCD was consistently greatest in animals on the high plane of nutrition and lowest in those on the low plane. Lactation did not appear to have a major effect on the rate of decline in the tissue concentrations of these compounds. No significant (P greater than 0.05) relationships were found between the concentrations of HCE or OCD in the subcutaneous fat and either milk or blood at any stage of the experiment. At slaughter, from 18 to 24 months after the commencement of the experiments, significant correlations (P less than 0.05) were found among concentrations of HCE and OCD in subcutaneous fat, renal fat and fat from the bone marrow.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between chlordane and its metabolites in blood of pest control operators and spraying conditions

Chlordane has been widely used to protect soil and house foundations against termite infestation. Pest control operators (PCOs) are occupationally exposed to chlordane. The relationship between chlordane and its metabolites in blood of PCOs and spraying conditions were investigated. Chlordane and its metabolites were detected in the blood of some chlordane-exposed PCOs, but not in that of the controls. Trans-nonachlor and the metabolites oxychlordane and heptachlor epoxide were detected in the blood of PCOs. Total concentration of chlordane and its metabolites in blood (trans-nonachlor + oxychlordane + heptachlor epoxide) was less than 5.6 ppb (mean: 0.89 ppb). The concentration of chlordane and its metabolites in blood of chlordane-exposed PCOs was significantly correlated with the number of spraying days and the amount of chlordane sprayed, particularly with a large correlation coefficient (r = 0.81, P less than 0.001) with the spraying days in the three months prior to the medical examination. The concentration of chlordane and its metabolites in blood is considered to be a useful indicator of biological monitoring for chlordane exposed workers (PCOs).

Comparative disposition and elimination of chlordane in rats and mice

The absorption, distribution and elimination of orally administered cis-[14C]chlordane (1.0 mg/kg) was determined in male Sprague-Dawley rats and C57BL/6JX mice. Absorption appeared somewhat slower in mice, but total [14C]chlordane equivalents at peak blood concentration (113 ng/ml at 8 h) exceeded the maximum which occurred in rats (81 ng/ml at 2 h). Peak tissue residues in both species were observed within 4 h, suggesting that the radiocarbon responsible for the latent peak blood levels in mice was eliminated rather than sequestered by the tissues. This was supported by the findings that peak tissue residue levels were lower in mice, and that the initial fecal elimination rate was higher than in rats. At 12 h, 34% and 7% of the doses were excreted in mouse and rat feces, respectively; by 3 days, both species had voided 83% of the dose in the feces. Clearance rates of tissue residues were markedly faster in the rat, and consequently, the total body burden resulting from chronic exposure to chlordane will be far greater in mice than in rats.

Residues and metabolites of selected persistent halogenated hydrocarbons in blood specimens from a general population survey

The National Center for Health Statistics collaborated with the National Human Monitoring Program of the U.S. Environmental Protection Agency (EPA) in a four-year study to assess the exposure of the general population to selected pesticides through analysis of blood serum and urine specimens. Specimens were collected on a national probability half-sample of persons 12-74 years of age from 64 locations across the United States comprising the sample areas in the Second National Health and Examination Survey (NHANES II) and analyzed for selected organochlorine, carbamate, chlorophenoxy and organophosphorus pesticides. Medical, nutritional and pesticide usage data are also available for each sample person. Results of the blood serum analyses indicate that the general population is being exposed to some of these types of pesticides. For selected pesticide residues, the percent quantifiable positives and median serum levels by age group are presented for three regions of the United States. Since 1970, EPA has conducted a national probability sampling of human adipose tissue. Specimens obtained on a survey design representative of the general population were analyzed for selected organochlorine pesticides and toxic chemicals. Findings from the 1979 survey also indicate exposure of the general population to some of these chemicals.